He said: "My first reaction is the reaction of anyone, which is real sympathy for him, anger at how he is being held by those people and an earnest hope that, despite all the difficulties, we can do something.

"But I just don't know if we are able to or not. There is no point in raising false hopes because of the nature of the people
we're dealing with."

However, he added the government was doing all it "properly and legitimately" could.

Delegates at Labour's annual conference in Brighton have voted to hold a debate on "Britain's role in Iraq".

'Power of prayer'

Dr Abdullah and Dr Hussain are not expected to have any direct contact with the kidnappers, but have said they wanted to get a "humanitarian" message to them.

"I think as fellow British citizens, it is our responsibility to do what we can. I believe in the power of prayer," said Dr Abdullah, who arrived in Iraq on Saturday.